Does Scotland’s Class 6H allow cooling?
Class 6H covers an air source heat pump used only for domestic heating or hot water, and the cited noise limit is 42.0 dB(A) (checked 25 Sep 2026). A unit that also cools is not covered by this class.
computed
The Town and Country Planning (General Permitted Development) (Scotland) Order 1992 (SI 1992/223), Schedule 1, Part 1A, Class 6H, as substituted by SSI 2016/126 and amended up to S
Instrument checked 25 Sep 2026. Version 1.0.0.
| Point | Clause | Quote | Source | Version | Checked | In plain words | Input |
|---|---|---|---|---|---|---|---|
| SCO-01 | Class 6H(1) | The installation, alteration or replacement of an air source heat pump on a dwelling or within the curtilage of a dwelling. | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | This proposal is not covered by this permitted-development class; a planning application may be needed. | Is the building a house, or a building that is wholly flats? |
| SCO-02 | Class 6H(2)(a) | if it would result in the presence on the same building or within the curtilage of a building of more than one air source heat pump | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | Scotland's Class 6H allows only one air source heat pump per building/curtilage. | How many outdoor units will the building have once this one is installed? |
| SCO-03 | Class 6H(2)(b)(i) | any part of the development would protrude more than 1 metre from the outer surface of an external wall, roof plane, roof ridge or chimney of the dwelling | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | Protrusion of more than 1 m from the wall/roof is not covered by Class 6H. | How far would the unit project from the outer wall, in metres?; Is the unit on the dwelling, or within the curtilage? |
| SCO-04 | Class 6H(2)(b)(ii) | the air source heat pump would be within a conservation area, unless the air source heat pump would be—(aa) at ground floor level; and (bb) on the rear elevation | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | In a conservation area, Scotland's Class 6H only permits ground-floor, rear-elevation installations. | Is this exact address inside a conservation area?; Would it be on the ground floor and on the rear elevation?; Is the unit on the dwelling, or within the curtilage? |
| SCO-05 | Class 6H(2)(c) | (i) any part of the development would be forward of a wall forming part of the principal elevation or side elevation where that elevation fronts a road; or (ii) any resulting structure would exceed 3 metres in height | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | A curtilage installation forward of a road-facing elevation, or over 3 m tall, is not covered by Class 6H. | Would it sit forward of the elevation that faces a road?; How tall would the resulting structure be, in metres?; Is the unit on the dwelling, or within the curtilage? |
| SCO-06 | Class 6H(2)(d) | if the air source heat pump would be within—(i) a World Heritage Site; or (ii) the curtilage of a listed building | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | World Heritage Sites and the curtilage of listed buildings are excluded from Class 6H. | Is this exact address in a World Heritage Site?; Is the building listed? A postcode search cannot clear this. |
| SCO-07 | Class 6H(3)(a) | the air source heat pump must be used only for the purpose of providing domestic heating or hot water | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | Class 6H covers air source heat pumps used only for heating or hot water; a unit that also cools is not covered by this permitted-development class — a planning application may be needed. | Will the pump be used only for cooling, or for heating as well? |
| SCO-08 | Class 6H(3)(c), inserted SSI 2024/102 art. 6(d)(i) | the air source heat pump must comply with MCS Planning Standards for air source heat pumps or equivalent standards | www.legislation.gov.uk/uksi/1992/223/schedule/1 | 1.0.0 | 25 Sep 2026 | Compliance with the MCS 020 (Issue 1.3) 42 dB(A) noise limit is required for this to be permitted development. | What is the noise result at 1 m outside the neighbour's nearest habitable-room window? |
| SCO-DEF | article 2(1), 'MCS Planning Standards', as inserted (24.5.2024) by The Town and Country Planning (General Permitted Development) (Scotland) Amendment Order 2024 (SSI 2024/102), arts. 1, 3(1)(a)(i) | “ MCS Planning Standards ” means the product and installation standards specified in the Microgeneration Certification Scheme MCS 020, Issue 1.3 | www.legislation.gov.uk/uksi/1992/223/article/2 | 1.0.0 | 25 Sep 2026 | This row defines a term the other rows use. | No extra input — this row is a definition or a dataset note. |
| SCO-A4 | article 4(1), 'Directions restricting permitted development' | the Secretary of State or the planning authority concerned may direct that the permission granted by article 3 shall not apply to—(a) all or any development of all or any of those classes in any particular area specified in the direction; or (b) any particular development, specified in the direction, falling within any of these classes | www.legislation.gov.uk/uksi/1992/223/article/4 | 1.0.0 | 25 Sep 2026 | An Article 4 direction applies here — the exact wording of the specific direction needs checking (it may or may not cover air source heat pumps). | Is there an Article 4 direction on this address?; Does that direction name this permitted-development class? |
| SCO-DATASET | n/a — Historic Environment Scotland coverage gap | No statutory sentence is stored for this row. It records a gap in the geographic file, and a missing row is not a clearance. | — | 1.0.0 | 25 Sep 2026 | Enter: Is this authority covered by the planning dataset that was consulted?. | Is this authority covered by the planning dataset that was consulted? |
| mcs020_legacy_scotland | Step 10 | Is the FINAL RESULT in STEP 9 equal to or lower than the permitted development noise limit of 42.0 dB(A)? | www.midsussex.gov.uk/media/9082/mcs-020.pdf | 1.0.0 | 25 Sep 2026 | The noise limit in this method is 42.0 dB(A). | Sound power of the outdoor unit, distance to the neighbour’s window, and directivity Q. |
Next pages
The Town and Country Planning (General Permitted Development) (Scotland) Order 1992 (SI 1992/223), Schedule 1, Part 1A, Class 6H, as substituted by SSI 2016/126 and amended up to SSI 2024/102 · 25 Sep 2026 · n=12 · Each row is a point in docs/decision-contract.yaml. The engine that scores them is scripts/contract_engine.py. · updated 25 Sep 2026 · version 1.0.0 · CSV of the values on this page
Source detail
https://www.legislation.gov.uk/uksi/1992/223/schedule/1